8a. Equisetum hyemale subsp. hyemale
木贼(原亚种) mu zei (yuan ya zhong)
Hippochaete hyemalis (Linnaeus) Milde ex Bruhin.
Plants large. Rhizome creeping or erect, blackish brown, nodes and roots with long yellowish brown trichomes. Aerial stem perennial, monomorphic, green, up to or more than 1 m tall, (3-)5-9 mm in diam. at middle, not branched or base with few erect lateral branches; internodes 5-8 cm. Aerial stem 16-22-ridged; ridges arc-shaped abaxially or nearly rectangular, with 2 rows of tubercles; sheath 0.7-1 cm, blackish brown or both distal portion and base with a blackish brown band, or only distal portion with a blackish brown band; sheath teeth 16-22, lanceolate, small, 0.3-0.4 cm, teeth of distal portion light brown, membranous, aristate, caducous, teeth of lower portion blackish brown, thinly leathery, abaxially 4-ridged at base, persistent or falling off early with sheath. Strobilus ovate, 1-1.5 cm, 0.4-0.7 cm in diam., apex with small acute tip, sessile.
Forests, stream banks; 100-3000 m. Chongqing, Gansu, Hebei, Heilongjiang, Henan, Hubei, Jilin, Liaoning, Nei Mongol, Shaanxi, Sichuan, Xinjiang [Japan, Korea, Mongolia, Russia; C and SW Asia, Europe].